The specific release of granular enzymes, studied in leukocytes stimulated by various hormones, therapeutic anti-inflammatory drugs, and/or particles, will be correlated with changes in intracellular levels of cyclic AMP and cyclic GMP, and with cyclic nucleotide-dependent phosphorylation and dephosphorylation of specific soluble and membrane-bound proteins. The subcellular localization and properties of cyclic AMP-dependent protein phosphorylation and dephosphorylation reactions in human PMN leukocytes will be studied. The role of protein phosphorylation in the binding and movements of lysosomes by microtubules will be investigated. The role of the microtubule-associated proteins (MAPs) in the attachment of lysosomes to microtubules in vitro will be analyzed and the effect of cyclic AMP-induced phosphorylation of the MAPs on the attachment will be determined. The role of the MAPs in the in vitro assembly of microtubules will be determined, and the effect of cyclic AMP-induced phosphorylation on the function of MAPs in the assembly process will be assessed. It will be determined if the MAPs contain ATPase activity and, if so, if this activity is modulated in any way by cyclic nucleotides. The protein kinases and protein phosphatases relevant to regulation of the functioning of human PMN leukocytes will be isolated and characterized.